One vertex per element, one color per generator, with an edge from x to x·s.
(6,9)(7,11)(13,14)(15,18)(16,20)(17,19)(21,22)(23,26)(24,29)(25,30)(27,32)(28,34)(31,35)(33,36) involution — undirected(2,4)(13,15,17,20)(14,18,19,16)(22,23)(27,29)(28,30)(35,36)(1,2)(3,4)(5,6)(7,10)(8,9)(11,12)(13,15)(14,16)(17,20)(18,19)(21,23,26,22)(24,29,32,27)(25,30,34,28)(31,36,33,35)(5,7,8,11)(6,10,9,12)(21,24)(22,27)(23,29)(25,33)(26,32)(28,36)(30,35)(31,34)(5,6)(7,10)(8,9)(11,12)(13,16)(14,15)(17,18)(19,20)(21,25)(22,28)(23,30)(24,31)(26,34)(27,35)(29,36)(32,33) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.